Check out the SERIAL type. It does precisely what you
want. An idea as to how this is used would be like
this:
CREATE TABLE foo ( prim_key SERIAL PRIMARY KEY, bar text
);
I tend to create sequences by hand like this:
CREATE SEQUENCE my_sequence_seq;
And then I create my table with a definition like
this:
CREATE TABLE foo ( prim_key int DEFAULT nextval('my_sequence_seq') PRIMARY KEY, bar text,
);
But that's just because I have been using PostgreSQL
long enough that it didn't have the SERIAL type when I
started. The SERIAL type is just syntactic sugar for
what I generally do the long way.
Either way you simply pretend that the column isn't
there when you do inserts (unless you know what you
are doing) like so:
INSERT INTO foo (bar) VALUES ('hello');
INSERT INTO foo (bar) VALUES ('goodbye');
And then when you select you get:
processdata=> SELECT * FROM foo;prim_key | bar
----------+--------- 1 | hello 2 | goodbye
(2 rows)
I hope that is helpful,
Jason Earl
--- Stefan Lindner <lindner@visionet.de> wrote:
> Is there any way to get system maintained keys from
> postgres? e.g. to
> have a table with a primary key column (varchar or
> int) and let postgres
> chose the next unique value for this column?
>
>
>
> ---------------------------(end of
> broadcast)---------------------------
> TIP 6: Have you searched our list archives?
>
> http://archives.postgresql.org
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